Like humans, some song sparrows are more effusive than others, at least when it comes to defending their territories. New findings from the University of Washington show that consistent individual differences exist not only for how aggressive individual song sparrows are but also for how much they use their signals to communicate their aggressive intentions.
The findings, published online Dec. 4 in Proceedings of the Royal Society B, show that while many birds signal their intentions clearly, other “strong silent types” go immediately to aggressive behavior and ultimately attack without first signaling their intentions. (more…)
Male birds use their song to dupe females they have just met by pretending they are in excellent physical condition.
Just as some men try to cast themselves in a better light when they approach would-be dates, so male birds in poor condition seek to portray that they are fitter than they really are. But males do not even try to deceive their long-term partners, who are able to establish the true condition of the male by their song.
Researchers at the University of Exeter’s Cornwall Campus studied zebra finches to establish how trustworthy birdsong was in providing honest signals about the male’s value as a mate. Singing is a test of the condition of birds because it uses a lot of energy. Fit and healthy birds are thought to be able to sustain a high song rate for longer, making them more attractive to females. (more…)
Warmer waters flowed to shelfbreak south of New England
At a meeting with New England commercial fishermen last December, physical oceanographers Glen Gawarkiewicz and Al Plueddemann from the Woods Hole Oceanographic Institution (WHOI) were alerted by three fishermen about unusually high surface water temperatures and strong currents on the outer continental shelf south of New England.
“I promised them I would look into why that was happening,” Gawarkiewicz says. (more…)
A classic study from more than 60 years ago suggesting that males are more promiscuous and females more choosy in selecting mates may, in fact, be wrong, say life scientists who are the first to repeat the historic experiment using the same methods as the original.
In 1948, English geneticist Angus John Bateman published a study showing that male fruit flies gain an evolutionary advantage from having multiple mates, while their female counterparts do not. Bateman’s conclusions have informed and influenced an entire sub-field of evolutionary biology for decades.
“Bateman’s 1948 study is the most-cited experimental paper in sexual selection today because of its conclusions about how the number of mates influences fitness in males and females,” said Patricia Adair Gowaty, a distinguished professor of ecology and evolutionary biology at UCLA. “Yet despite its important status, the experiment has never been repeated with the methods that Bateman himself originally used, until now. (more…)
